A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
E
E.C. (E): European Commission (Executive).
E.C.U.: Electronic Control Unit.
E.M.F.(emf.): Electro Motive Force.
Early Fuel Evaporation: Early fuel evaporation system using a heater element below a carburettor to heat the intake air and improve atomisation at cold engine speeds. Improves driveability and reduces harmful exhaust emissions.
Earth (Ground): The electrical termination for components connected into a vehicle direct current earth return circuit. On mains electricity a safety route for an electrical short circuit used as a means of protecting people or electrical components from electrical overload.(Ground - US term)
Earth (Ground) Cable: The battery cable connecting the return side of a vehicle circuit to a terminal on the battery where a ground return circuit is used. (Ground - US term).
Earth Switching: Used to describe a circuit where the switch breaks the earth side of the circuit instead of the supply side.
EATX: Electronically controlled automatic transmission.
ECAT: Electronic Control of Automatic Transmission
Eccentric: Off centre. Usually refers to a rotating component with the operational part rotating about the central axis of the shaft. An example is a round cam offset from the shaft axis.
ECM: Engine control module. The electronic control module for engine management systems.
ECT: Engine coolant temperature sensor or sender.
ECU: Electronic Control Unit.
EDC: Electronic Diesel Control.
EDIS: Electronic distributor or distributorless ignition system.
EEC: Electronic engine control module.
EFE: Early fuel evaporation system using a heater element below a carburettor to heat the intake air and improve atomisation at cold engine speeds. Improves driveability and reduces harmful exhaust emissions.
Efficiency: A measure of effectiveness given as a ratio, percentage or decimal value (co-efficient) based on actual and possible performance.
Effort: A force or action that tries to achieve something.
EFI: Electronic fuel injection using sensors, an electronic control unit and fuel injectors to spray fuel into a central throttle body or the inlet ports. Provides very close control of fuel mixture under all operating conditions.
EGO: Exhaust Gas Oxygen Sensor. Also HEGO - Heated Exhaust Gas Oxygen Sensor, EOS Exhaust Oxygen Sensor and Lambda sensor. Provides information to the fuel system ECU on the oxygen content in the exhaust gas.
EGR: Exhaust gas recirculation. An emission control system that uses an exhaust gas feed into the intake air stream to reduce the mass of oxygen in the air charge and limit the formation of harmful oxides.
Elastic Limit: Amount of deflection in a spring that can be tolerated before permanent deformation occurs.
Elasticity: The property of materials that can deform and return to their original shape without permanent deformation.
Electric Field: Area round an electric charge in which an electric force is exerted.
Electrical Energy: The potential of electricity to do work.
Electro Motive Force (emf.): Electrical energy available to a circuit at the battery or generator.
Electro Plating: Coating with chromium, silver, etc. by electrolysis.
Electrode: An electrical conductor into an electrolyte, for producing an arc or a terminal in an electronic valve.
Electrohydraulic: A combination of electrical and hydraulic control systems.
Electrolyte: A liquid that conducts electricity. Battery acid is a good example.
Electromagnet: A magnet formed by a soft iron core and an electrical winding about the core. Becomes a magnet when an electrical current flows through the windings.
Electromagnetic: See electromagnet.
Electromagnetic Oscillation: Changes from one value to another in a circuit. Usually produces a sine wave output or similar.
Electromagnetic Solenoid: A solenoid (coil of wire) that is used to operate an actuator such as a fuel injection.
Electromagnetic Valve: A valve that is operated by a coil of wire, which becomes magnetic when switched on.
Electron: Electrons form the outer shell layers of atoms and orbit the protons and neutrons in the nucleus. The electrons have negative polarity and are electrically negative in opposition to the positive charge of the protons.
Electron Shell: Term used to describe the orbit of electrons round a nucleus.
Electronic: Electrical systems operated or controlled by semi-conductor devices.
Electronic Control: System usually based round an electronic control unit where the operation of the system is pre-programmed.
Electronic Ignition: Petrol ignition system in which switching semi-conductors make and break the low tension circuit.
Electrostatic: Describes the electrical state of something as in static (not flowing) electricity.
Element: The basic form of a material.
Emergency Brake: A legal requirement for all vehicles provided by a split hydraulic circuit or a mechanically operated parking brake.
Emery Paper: Carborundum grit on a backing sheet.
Emission Control: Systems on the vehicle to control (limit) toxic emission.
Emission-control: Systems on the vehicle to control (limit) toxic emission.
Emitter: Terminal of a transistor that becomes conductive when the base is energised.
Emulsion Tube: Combined main and compensating jet tubes in a carburettor with provision for drawing air into the fuel flow to create an emulsion at higher engine speeds, thus preventing over-richness and improving fuel distribution.
End Float: Longitudinal play in shaft, intentional or otherwise.
End Play: Alternative term for end float. Longitudinal play in shaft, intentional or otherwise.
Energy: An ability to perform work. SI unit is the '
Engagement: The act of making a connection between two gears of through a clutch.
Engaging Pin: A simple pin used to make a drive connection.
Engaging Plunger: General term to describe a plunger that engages something! Often part of a gearbox.
Engine Analyzer: Complex test equipment used to check a variety of engine operating functions and conditions. An oscilloscope is usually included.
Engine Block: Main part of the engine that contains the cylinders.
Engine Compartment: The space under the bonnet!
Engine Load: How hard the engine is having to work. For example, accelerating uphill creates a high load.
Engine Management: General term used to describe the control of engine operating functions such as ignition and fuelling. Usually related to electronic control.
Engine Map: A three dimensional map held in a microprocessor that provides an optimum set of values for the control of ignition timing, ignition dwell period and fuel quantities for all engine operating conditions.
Engine Speed Sensor: Provides information on engine speed to engine management systems (transducer).
Engine Support Beams: A bar that is used to support an engine, for example, after the transmission has been removed.
Engine Temp. Sensor: Engine temperature sender unit for temperature gauge and engine management systems (thermistor).
Engine Torque: The amount of turning force produced by an engine. Usually quoted at a set speed.
Enrichment: Process of increasing the mixture strength / reducing the air fuel ratio.
EOS: EOS Exhaust Oxygen Sensor. Provides information to the fuel system ECU on the oxygen content in the exhaust gas. Also EGO Exhaust Gas Oxygen Sensor, HEGO Heated Exhaust Gas Oxygen Sensor and Lambda sensor.
EPA: Environmental Protection Agency
Epicyclic Gear: See Epicyclical Gearing.
Epicyclical Gearing: A gear system, consisting in basic form of an internally toothed annulus or ring gear and a central externally toothed sun wheel, with usually three or four planet wheels or gears meshing with the sun wheel and annulus. The planet wheels are often carried as a unit on a planet carrier or spider. Holding the rotation of the planet carrier, annulus or sun wheel will provide a transmission ratio between the two remaining elements. Planetary gear sets can be coupled to increase the available number of ratios.
EPROM: Erasable Programmable Read Only Memory.
EPT: Exhaust Electronic Pressure Transducer.
Ethanol: Ethyl-alcohol produced from starches and sugar plants and used as an octane enhancer.
Ethylene Glycol: Anti-freeze. Chemical used to lower freezing point of coolant.
Evaluation Circuit: An electronic circuit used to decide a course of action.
EVAP: Emission control system that uses a charcoal canister to prevent fuel tank vapours from venting to the atmosphere. The vapours are drawn into the engine during specific running conditions to purge the canister.
Evaporation: The change from liquid to vapour or gas.
Evaporative Canister: A canister usually containing charcoal that prevents emissions from the fuel tank due to evaporation.
Evaporator: A radiator in the air conditioning system fitted in the heater and A/C housing. The refrigerant passes through the pipes in the evaporator and vaporises to absorb heat and therefore cool the air stream flowing into the vehicle passenger compartment.
EVR: Electronic vacuum regulator solenoid on EGR system.
Excess Pressure Valve: A pressure relief valve that opens if pressure exceeds a set value. Often for safety reasons.
Exhaust Blow-by: Gases from the exhaust bypassing a component, for example, the piston rings or a valve in a turbocharger.
Exhaust Emissions: Substances vented into the atmosphere from an exhaust system.
Exhaust Gas Analyser: An instrument for measuring the constituent gases in the exhaust.
Exhaust Gas Analyzer: An instrument for measuring the constituent gases in the exhaust.
Exhaust Gas Recirculation: An emission control system that uses an exhaust gas feed into the intake air stream to reduce the mass of oxygen in the air charge and limit the formation of harmful oxides.
Exhaust Manifold: Heat resisting ducting that connects the exhaust ports of an engine to an exhaust pipe.
Exhaust Ports: Outlets in the cylinder head for the exhaust after the valve opens. In a two-stroke engine the ports are in the side of the cylinder.
Exhaust Stroke: The last stroke of the four stroke cycle when the burnt gases are expelled to the atmosphere.
Expansion: An increase in size. For example, when a metal rod is heated it increases in length and diameter. Opposite of contraction.
Expansion Box: Open muffler in the exhaust system to reduce the noise.
Extension Housing: Usually describes an extra housing on the rear of a transmission gearbox.
External Customer: One outside of an organisation.